Heat exchanging system



Jan. 11, 1939. I J. GAUDl l I ,143,873

HEAT EXCHANGING SYSTEM Filed Dec. 31, 1935 lrrn ' INVENTOR. John B.GdUd/Ifi.

ATTO By Patented Jan. 17, 1939 PATENT v OFFICE HEAT nxonsnenvo sys'rm WeJohn B. Gaudin, New York, N. Y. Application December 31, 1935, SerialNo. 50,945

4 Claims. retest-.141 v This invention relates to heat-exchangingsystems, especially to radiator devices for use in such systems, andmore particularly to a known type of radiator characterized by so-calledfins usually comprising thin sheets of metal associated inheat-conducting relation with more compact heated conduits or bodies,and so disposed as to transfer the heat therefrom to the surroundingatmosphere or other fluid environment.

The efficiency secured in systems including fin-type radiators soconstructed leaves much to be desired, and the problem of increasingthis efficiency, while retaining the desirable structural featurescharacteristic of the fin-type ra-V diator unit, has been the subjectofprolonged research and experimentation by heatingengineers, with resultsnot entirely satisfactory.

As the outcome of my own investigation of this problem, I havediscovered that a prime obstacle to economical transfer of the heatavailable under such conditions is to be attributed to inefilcientprovision for rapid heat conduction in the vicinity of the centralconduit for the heating medium, this being due to the small mass of themetallic body at the region of the connection between the fins and theconduit, so that the heat hasbeen so sluggish in its emergence to thespace to be heated that the advantage of the fin-type members has beenpractically lost.

The general object of the present invention is to provide, in a heatingor heat-exchanging sys-' tem of the class described, and in whichfin-type radiators are employed for the sake'of their characteristicadvantages, various improvements in structural form of the componentelements of the typical fin-type radiator unit, and also improvements inthe co-ordination of such fin-type units as co-operatinginstrumentalities for the transferof heat to the space to be heated,which improvements will obviate to a great extent, if

not entirely, the aforesaid disadvantages, and I will advance theperformance of the fin-type radiators toward their optimum degree ofemciency and economy.

In pursuance of this general'obiect, an object of the invention is toprovide a laminated, tubular, heat-conducting body, along the entirelongitudinal axis of the radiator, adapted to yield rapidly to the finsa maximum amount of the,

heat carried by its fluid heating medium, and another object of theinvention is to avoid entrapment of heat centrally within the fins;also, as a means to this end, to provide for the better circulation ofair in the interstit al spaces of the assembly of fins, and for thefreer flow of'said air therefrom after it shall have been heated, withmore rapid, more uniform, and more complete, transfer of the heat socommunicated to this circulating air, such heat transfer being greatlyimproved by my novel arangements herein disclosed, inasmuch as the airis caused thereby to flow rapidly between the-heated fins, and to flowtherefrom into the circumambient atmosphere of the space to be heated,to which the heated air in transit acts to transfer its heat by theknown and rel able operation of convection and diffusion.

A cognate object of the invention, in pursuance of the aforesaid generalobject, is to effect such a change in the physical structure of the fincomponents as to provide a novel, shorter path for transfer of heat fromthe center of the fin structure to the periphery thereof by direct,

metallic conduction, this path being provided in the form of sheet-metalcomplemental fins lying in planes substantially parallel with, andcontiguous to, other, fluted fins which are disposed in a series themembers of which extend radially from the ,axial conduit of theconduit, 1. e., at right angles thereto, the flutings of the lastnamedseries co-operating with the flat surfaces of the fins in thecomplemental series to form of such contour or cross-section as toreduce the discrepancies in the lengths of the paths by which heat isconducted metallically from the centers'to themargina of the fins. Suchan improved conduit may take desirably the form of a rather flatelliptical or oblong tube, i. e., one

that is sensibly oblong in cross-section.

Among other obiectsof the invention are the provision of improved meansby which the novel f fin-type radiator structure embodying the sevi eralfeatures already disclosed briefly, and to be described more at lengthhereinafter, may be supported in use, and co-ordinated with themiceconduits of existing heating, or heat-exchanging. systems, to which itis desirable that my improvements shall be applicable without essentialdisturbance of those systems, and among such adapter means are includedheader and coupling devices to be described.

Other objects and advantages will appear as the description of theparticular physical embodiment selected to illustrate the inyentionprogresses, and the novel features'of 'the 'invention will beparticularly pointed out in the appended claims.

In describing the invention in detail and the particular physicalembodiment selected to illustrate the invention, reference will be hadto the accompanying drawing, and the several views thereof, wherein likecharacters of reference designate corresponding parts, and in which:

Figure 1 is a view in plan, partly in horizontal section, of a fin-typeradiator in the construction of which the present invention has been ema ed;

Fig. 2 is a plan view of a modification;

Fig. 3 is a view in vertical section on the line 33 of Fig. 1;

Fig. 4 is a view in elevation of one of the planiform fin elements takenseparately;

Fig. 5 is a fragmentary, detail view of the header parts and centralconduit, in assembled relation, and taken separately from the fincomponents; V

Fig. 6 is a. detail view in front elevation of one of the header parts,taken separately; and

Fig. '7 is a similar detail view of the complemen tal header part, alsotaken separately.

In a now-preferred embodiment of the invention selected for illustrativedisclosure herein, the part designated'by the reference character Ii isa conduit, preferably made of copper, or of an alloy of copper, onaccount of the superior heat-' conductivity, resistance to corrosion,and other desirable properties which qualify that metal for use insystems intended to circulate fluids for household heating, forrefrigeration, and for heat-interchange in many of its otherapplications; and in pursuance of an important feature of the presentinvention, to which a brief reference has been already made, thisconduit'ispreferably characterized by having an oblong crosssection, orone that is generally elliptical. in contour, the primary object of suchformation of the conduit beingto permit the assembly therewith of finshaving a rectangular, or other, noncircular contour which facilitatesoptimum occupation usefully of a given cubical space, while preservingthe advantages of uniform radius of direct metallic heat-conductionwhich has been heretofore characteristic onlyof fiat circular finsassociated with a central conduit of circular cross-section.

In' the structure illustrated herein, merely by way of example, I haveprovided two series of fins,

preferably made of the same material, .1. e., of copper, or a copperalloy of suitable composition,

having due regard to the necessarythinness of the sheet 'metal of whichthe fins are composed, the several members of these series respectivelybeing designated by the reference characters i2 and II, the latternumeral being applied to each of a series of fin members or componentscharacterized by having the form of fiat plates, or having a generalplaniform conformation; the components of the other series beingcharacterized by a fluted conformation; and thecoinponents of bothseries having a common, rectangular form, substantially oblong, intheinstance illustrated, this not being intended, however, to exclude theuse of other non-circular shapes.

The flutings c of the fin components ll may be desirably made in azig-zag conformation, as shown clearly in Figs. 1 and 3, and thisfiuting resembles conventional fiuting of suchfins in general contour,-but difiers preferably thereas shown in Figs. 1 and 3. The latter figureshows from substantially in various features which I have discovered toyield improved efllciency of a very high order in the transmission ofheat between the contiguous walls of the fins and the fluid medium. suchas air, circulated thereover.

One of these differences resides in the sharper pitch of the walls 0, ascompared with earlier types of fluted fins, and I secure thereby anincrease in the area available for heat-exchange within a given cubicalspace, as compared with the known types of fluted fins. Anotherdifieronce-emerges in the shape of the walls, as clearly seen in Figs. 1and 3. The walls 0 run from end to end of the fluted fin of my noveltype, and a series of long, parallel, vertical channels or flues F isthus provided, in which the circulated air or other fluid may flow withuninterrupted continuity, promoting optimum heat-exchanging efficiency.

These flues, in fact, are of ideal form to co-operate in imparting tothe ascending air the kinetic energy derived from the heated conduit ii,and so hastening its speed of circulation, for no space whatever iswasted, and there are no regions where the upward draft is materially,checked. The channels of narrowest cross-section are those at thelateral margins, and those near the middle, and all of the other fiuesmay be of approximately double the cross-section of the outermostlateral fiues, as is clearly shown.

The innermost are only constricted at the region of greatest heat,namely,.along the straight sides of the tube H, and it is desirable thatthe swiftest flow of air shall occur at this region,

which is in fact the case, so that in this respect my novel dispositionof the walls with their fluelike contour is more correct theoreticallythan the disposition provided for by known types of fin radiators. I

In pursuance of what may be regarded as the underlying object of thepresent invention, i. e., the creation and maintenance of directmetallic conduction of heat from the tube II, which is its prime sourcewithin the radiator, in the instance illustrated, and in order to efiectequalized transfer of this heat to the circumambient atmosphere of thespace to be heated, I have provided, in the series of fin elements ii. aheat-conductive instrumentality which is novel, both in' the idea ofmeans which it embodies,'and in its combinative relationship with thebetter known fluted-type fins l2.

The fins it are formed separately from the fins l2, and each fin i3comprises a plate or planiform body part, which is preferably ofrectangular or other non-circular form, and desirablyof approximatelythe oblong shape shown in Fig. 4, and it is illustrated as havingmarginal flanges ll suitably spaced apart to receive between them. andto fit over, the outer marginal edges l2 of the fluted fin componentsl2, as shown in Figs 1 and 3.

The fin components of each series are severally provided with bodyorifices respectively, so that theycan be assembled in tandem relationupon the conduit ll. As illustrated, these orifices are surrounded byhollow bosses l2." and I8" respectively, of which the bosses I!" are thesmaller, being adapted to ,fit snugly upon the conduit ll,

70 also how the bosses i2" fit snugly upon the bosses l3", andpreferably each of the bosses is slightly coved, as indicated at c', inFig. 4, so that they may be more readily assembled with a force fit uponthe conduit.

In so assembling them, it is convenient, first, to force a planiiorm fincomponent of the series I3 upon a conduit ll of. suitable size, and thento force a fluted fin component of the series I! into the position shownnear the left-hand end of Fig. 1, its boss l2" being forced upon theunderlying boss I3"; so that there is at that region a triple-laminated,heat-conductive wall or body in which the concentric bosses re-inforcethe underlying parallel conduit walls, and act as.

mental planiform'fin-component l3 may be considered to constitute acompound fin; and each successive compound fin so constituted may beconveniently installed by forcing its members into place seriatim;although this suggestion is not intended to exclude the adoption of anyother convenient procedure in fabricating-an assembly of the typeillustrated.

Again, the closely set relationship of adjacent compound fins, asillustrated in Fig. 1, has the desirable effect that the body part ofeach succeeding planiform fin component serves in a complemental fashionto complete the structure of the triangular channels or flues F whoseother two walls are formed by flutings of the fluted fin component.

Furthermore, the planiform body portions. it, which derive heat bymetallic conduction directly from the relatively long, parallel,mutually contiguous areas of contact between their bosses It" and theunderlying conduit M, are, by virtue of the radially extending, unbrokenbody portion it, of each such component, endowed with a novelcharacteristic capacity to transfer heat by metallic conduction over theshortest possible route toward the periphery of the radiator.

As the distances radially, from the axially disposed oblong tube ll aresubstantially equal for each point on the periphery, which equalityclearly appears from the showing in Fig. 4, it is evident that I haveprovided for a more uniform distribution of conducted heat than hasheretofore been possible-with the use of such fin-type radiators as haveutilized round ,conduits and square fins, even when the fins werecorrugated.

The disposition of these compound fins in contiguous relation with eachother according to my invention, serves an extremely. important furtherpurpose, moreover, in that the heat in course of transfer from the coreto the periphery of the radiator structure, is tapped oil from theplaniform fins by the fluted complements] fin components at all suchregions of contact therebetween as are designated by the referencecharacters c.

Without elaborating the description of this service, which is readilyunderstandable from the disclosure in the drawings, it will sufllce tosay that, not only does heat travel laterally from the fiat wall portionof conduit H along the tortuous path afforded for metallic conduction bythe zigzag walls of the fiutings, but at each linear contact, as c, thefin component 12 receives from the fin component I! an increment of heatby direct- I metallic conduction. This heat-increment has only travelledover one-half of the distance from its source that must be travelled byheat conducted over the tortuous path, and is thus adapted to reinforcethe heat available for the member l2 to carry to its further reaches,and so a'desirable and novel transfer and equalization of heat iseifected until, by the time the periphery of the radiator is reached,substantially all of the heat units which were available for transfer tothe currents of air circulated upwards through the flues F between thefin components has been so transferred, and the transfer has beenaccomplished in the most efilcient manner because none of the availableheat has been entrapped or lost.

Again, it will be noticed that each flue is formed by two walls offiuting and one, relatively fiat, wall formed by the fiat fin, so thatthe combined heat made available by each type of conduction isefiectively distributed throughout the radiator.

It is evident that the size of the radiators can be extended to anindefinite length, within practical limits, according to therequirements of individualinstallations, and that no separately formedboundary wall members have to be prosion and contraction oi. the systemis self-compensating throughout, and does not set up deleteriousinternal tension, so that no undue strain is imposed upon the conduit,nor is there undue compressionof the fin components. If extremeconditions of heat should supervene, conceivably the expansion of thefluted members l2 might force the flanges i3 outwardly and cause atelescopic readjustment to take place as between adjacent compound fins,but without harm to the system. Such telescopic arrangements are withinthe scope of the underlying idea of means, and in general the particularphysical embodiment disclosed is to be regarded as illustrative ratherthan, limitative.

Wide range is possible in the selection of fittings and as a convenientand now-preferred form of fittings I have shown at each end of theconduit l l a fitting which is desirably simple, but efllcient for theintended use, as it afiords a practical means for connecting such aradiator with the domestic heating pipes of a dwelling, or in any otherheat-exchanging system for which the system of fin-type radiatorembodying my improvements may be available.

Each fitting includes a female part 2! and a male part 22, these partshaving complemental surfaces adapted to be fastened together by bolts23, leaving, as at 28, a slight clearance conform ing in general contourto the end of conduit H,

- which is desirably flared, as at I l x, to be clamped in the mannershown in Figs. 1 and 5. The

member 22 has a nozzle 25 suitably threaded forin Fig. 2, where thecompound fin elements F may each be considered to embody a fluted fin,as l2, and a fiat fin, as l3, combined and cooperating as alreadydescribed with respect to 5 the parts so designated in the structuredisclosed in Figs. 1 to 4.

Each compound fin in this modification is, however, of greater dimensiontransversely of the radiator assembly, than are those shown in Fig. 1,and the modified assembly is arranged to be heated by two stretches ofconduits HA and HE, which are assembled with the fins in a manner likethat already described at length, except that each fin component has twooblong bosses, arranged in parallelism, as will be readily understoodfrom the disposition of the dot-dash lines designated by the referencecharacters HA and MB in Fig. 2, without further illustration.

Each fitting for this modification comprises a female part 2| with twoopenings each registering with an end of one of the tubes HA. and Brespectively; also a male part 22 is provided, having portions similarto those of the male member 22 of Fig. 1, adapted to hold the ends ofthe 25 tubes HA and HE, as the case may be, in a clearance like thatindicated at M in Fig. 5.

The parts 25' may be formed as manifolds of conventional form, and itwill be understood that the irregular lines in Fig. 2 are intended toindicate indefinite extension horizontally of the units,

which will be governed by considerations of convenience, economy andeconomy in operation, just as in the Fig. 1 form of the invention.

There may be as many of the central tubes,

like those indicated at IA and l lB as may prove to be desirable inaccordance with the requirements of any given installation.

Instead of a tubularconduit for heat-conduct ing fluids, the member Ilmay be substituted by an elongated heat-conductive'body of any suitablecharacter, as, for example, an electrically energized resistor elementof any suitable character and contour.

I claim:

1. A heat-exchanging appliance for a heat-exchanging system of the classdescribed; said appliance having the features claimed in claim 4, and inwhich the heat-conductive member is made as a thin, sheet-metal conduitfor fluid, and said fins are respectively polygonal in shape, theflutings and contiguous radial body portions forming parallel verticalflues between the fins and open from end to end of the fins, whereby aheat-transferring fluid may be circulated in 5 said flues in such amanner as to be discharged forcibly therefrom to a circumambient body offluid.

2- An assembly of fin elements in a heat-exchanging appliance of thefin-type; said assembly comprising a set of complements! fin elements,one having a fluted body portion and another having a planiform bodyportion with which said flutings co-operate to constitute furrows; andeach of said elements having a hollow boss serving to support saidelements in complemental relative position and in heat-exchangingfitment upon an elongated heat-conductive member common to both of saidelements, said bosses overlapping each other throughout the inter-finspaces and constituting, with the underlying portions of saidheat-conductive member, a triple-laminated structure.

An assembly of fin elements in a heat-exchanging appliance of thefin-type; said assembly including an elongated heat-conductive member ofsubstantially oblong cross-section extending to an indefinite extentalong the major axis of the appliance; and a plural series of finelements, the members of the two series being arranged in alternatingdisposition, the members of one series respectively having planiformbodies, and the members of the other series respectively having flutedbodies, whereby said elements cooperate to form fiues therebetween, andthe respective fin elements each having a boss surrounding saidelongated member, said bosses over-lapping each other throughout theinter-fin spaces and constituting, with the underlying portions of saidheat-conductive member, a triplelaminated structure.

4. A heat-exchanging appliance for a heat-exchanging system of the classdescribed; said appliance having an elongated heat-conductive member,and pairs of radiating fins with complemental bosses arranged incontiguous, abutting series along said member, one fin-component of eachpair comprising one of said bosses fitted closely upon said member,extending along the same for the entire width of the pair, with aradially disposed, integral body portion of sheet metal, and another,complemental fin component having a boss fitted closely upon saidfirst-named boss with an integral body portion of sheet metal havingzig-zag flutings disposed between, and contacting with, the radiallydisposed body fin of the same pair and the radially disposed body fin ofan adjoining pair, whereby said elongated member constitutes, with saidsuperimposed bosses and the integral portions angularly connecting thebosses with their respective fin body portions a unitary,triple-laminated heat-conduc tive central metallic structure which maybe extended to any desired extent lengthwise by the addition of similarcomplemental pair components in alternating order.

JOHN B. GAUDIN.

